Nevada Solar Plant Harnessing Desert Sun

By Catherina Elsworth
March 7, 2008

A field of adjustable mirrors covering a barren patch
of the Nevada desert is generating power to help fuel the neon lights
and hotels of the Las Vegas strip, thanks to a little known type of
solar power gaining currency across the US and beyond.

Nevada Solar One lies some 20 miles south of Las
Vegas and is one of two prototype plants to utilise the technology that
recently opened in the US. It is capable of producing enough electricity
to light up 14,000 homes.

Another 10 such plants are in advanced stages of
planning in California, Arizona and Nevada, the New York Times
reports.

When the sun is strong, the 10 plants will have the
potential to generate as much electricity as three nuclear reactors but
can be built in a fraction of the time it takes to construct a nuclear
facility.

Unlike solar power from photovoltaic panels attached
to roofs, the desert mirrors focus the sun's rays on to black pipes
containing a synthetic oil which is used to boil water until it becomes
steam. The steam is then used to drive a turbine that generates
electricity.

Although not new, the technology is suddenly in high
demand given the soaring price of fossil fuel, concerns about the
environment and recent mandates in several states that require utility
companies to obtain more power from renewable sources.

Nevada Solar One, built by a Spanish company,
Acciona, contains 182,000 curved mirrors covering nearly a square mile.
Each mirror magnifies the sun's rays 70 times and is adjusted by
computerised controls to track the sun as it moves across the sky,
maximising energy production. The area typically gets 330 days of
sunshine a year.

As well as the US plants, eight are being built in
Spain, Algeria and Morocco with another nine projects in the pipeline
across Europe, Asia and Africa, according to Frederick Morse, an energy
consultant and former head of solar energy at the US Energy
Department.

Mr. Morse told the New York Times that solar thermal
plants could meet much of the soaring energy demands of desert cities
such as Phoenix, Las Vegas as well as much of the southwestern United
States.

Some experts even believe the powerful desert
sunshine in Arizona, New Mexico, California and Nevada has the potential
to meet the energy needs of the whole of the US, although this would
require costly extensions of transmission infrastructure into remote
desert areas.

A system utilising this type of solar thermal power
was developed in the 1980s when a series of plants were constructed in
California's Mojave desert. But although relatively inexpensive, the low
price of natural gas in the 1990s made the plants uneconomic.

The situation has since changed making the plants
economically viable. Solar plants also receive a federal tax subsidy.
Nevada Solar One is the first major solar thermal project to be built in
over 16 years.

Last month, a 280-megawatt solar thermal plant was
announced in Phoenix, Arizona, which will be built by another Spanish
company, Abengoa, and finished in 2011. It will rank as the largest such
project in the world and be capable of storing heat to continue
producing power for several hours after the sun sets.

Manufacturers of solar thermal equipment are braced
for a surge in demand. A Las Vegas company, Ausra, is building a factory
to make mirrors for one type of solar plant, while German company,
Schott, announced it is building a factory in Albuquerque that will
produce both photovoltaic panels and receivers for solar thermal power
plants.